1. Technical Field
The present invention relates to an alignment jig and an alignment apparatus for a liquid-jet head, which are useful, particularly, when used in high accuracy alignment of the liquid-jet head with an alignment mark printed on a mask as a transparent member; and also relates to a method for producing the liquid-jet head.
2. Related Art
An ink-jet recording apparatus, such as an ink-jet printer or an ink-jet plotter, is equipped with an ink-jet recording head unit (may be hereinafter referred to as a head unit) including an ink-jet recording head which ejects, as ink droplets, ink accommodated in a liquid accommodation portion such as an ink cartridge or an ink tank. The ink-jet recording head has nozzle rows comprising rows of nozzle orifices arranged in parallel, and has its ink ejection surface side covered with a cover head. The cover head has a window frame portion having an opening window portion provided on the ink droplet ejection surface side of the ink-jet recording head for exposing a nozzle opening, and has a side wall portion formed by being bent from the window frame portion beside the side surface of the ink-jet recording head. The cover head is fixed by having the side wall portion joined to the side surface of the ink-jet recording head (see, for example, JP-A-2002-160376 (page 4, FIG. 3)).
When the cover head and a fixing member, such as a fixing plate, are to be joined to a plurality of the ink-jet recording heads, the ink-jet recording heads are moved with respect to the fixing member for predetermined positioning so that an alignment mark provided in a nozzle plate aligns with a reference mark provided in a flat plate-shaped glass mask. The reference mark is generally formed on the surface of the glass mask by chrome printing or the like (see, for example, JP-A-2004-345281 (page 10, FIG. 3)).
However, when the reference mark is formed on the surface of the glass mask, as mentioned above, the problem arises that the reference mark is damaged by chipping or scarring, for example, due to the contact of the surface of the glass mask with the liquid-jet head. To achieve high accuracy positioning, the distance between the reference mark and the alignment mark needs to be minimized. Nevertheless, it has been difficult to support the nozzle plate directly on the surface of the glass mask via the fixing member.
To raise the accuracy of alignment, it is necessary to increase the magnification of an optical system in an optical means for observing the reference mark and the alignment mark. When the magnification is increased, however, the reference mark needs to be rendered smaller and to be formed from thinner lines, in accordance with the increase in the magnification. The smaller and the thinner the reference mark becomes, the higher the risk of the aforementioned chipping or scarring becomes.
Such a problem occurs not only with alignment associated with the production of an ink-jet recording head unit, but also with alignment associated with the production of other liquid-jet head units.